Many types of display boxes are known provided with elements which retain and protect a container housed therein such that the base of the container is kept raised from the base of the box to protect it from possible impacts while transporting or storing the boxes with the containers therein or while moving them from one place to another. A box of this type is illustrated, for example, in EP-B-0642977 and in the corresponding U.S. Pat. No. 5,540,330; it is formed from a single piece of punched and crease-lined cardboard having projecting flaps at one end, these flaps being automatically folded about themselves (on shaping the box) to form supports which are only partly glued onto the side walls of the box and perform the effective function of keeping the container housed in the box raised and spaced from the adjacent base of the box.
EP-A-0761550 describes a display box also formed from a single piece of punched and crease-lined cardboard which differs from the box claimed in the aforesaid patents by the fact that one of the flaps projecting from an end of the cardboard sheet is very long and, in addition to forming a portion for supporting the container base (by keeping it raised in front of a window provided in the side wall of the box), extends (while remaining adhering to a side wall of the box) beyond the opposite end of the box and is partly glued to a flap projecting from said opposite end: in this manner, when the cardboard sheet is folded to form the finished box, the said very long flap forms two separate supports, one for the lower end of the container and the other for the upper end of the container, which is hence securely retained in the box and is protected against those impacts which may be transmitted to the two lids or ends of the box.
The main drawback of known display boxes is that nothing effectively prevents the containers from rotating (as a result of the handling and transport to which the finished boxes are subjected) about their longitudinal axis, so that any portion of the cylindrical surface of the containers can appear visible through the windows provided in the box, rather than only and always that portion carrying trademarks, writings, labels or the like which are required to remain positioned in front of the windows provided in the boxes.